Process for the production of alkyl ester salts



Patented M UNITED STATES. PATENT OFFICE alszaoa I v Call! No Drawing.

a corporation of Delaware Application June. 2.4, 1935, Serial No. 2am. In the Netherlands July 3, 1934 4 Claims, (01. 200-460) This invention relates to the production of salts of alkyl esters of polybasic acids and is par ticularly concerned salts from the reaction products of oleiines with "5. nolybasic acids.

r We have found that alkyl ester salts of excel-, lent properties are obtained when hydrocarbon" material containingat least paraflln' wax is selected as initial material for manufacturing by 1 heat treatment the oleflnes to be reacted with the polybasic acids. It was further ascertained that the higher the wax content of. the initial material, the better the final products, provided that the composition of the remaining part of the initial material remains substantially the.

same. Thus material containing at least 50% paramn wax is, as a rule, preferred to material containing about wax, whilst excellent alkyl ester salts result from the selection m of pure or substantially pure paraflln wax, or 'othermaterial of very high paraiiin wax content, as initial material.

According to the invention such mineral oils or tar oils, e. g. brown-coal tar oils, may be used as are rich in paraflin wax as well as their wax-,

containing distiliates orresidues. Petrolatum,

ozoberite wax, slop-wax, illterpress cakes or other hydrocarbon waxes or materials substantially consisting of paraiiin wax are found to be ex- 30 cellent initial for producing by heat 7 treatment the unsaturated hydrocarbons to be reacted with the polybasic acids.

The heat treatmentto be applied to the waxy material may comprise a cracking treatment,

8 preferably in the vapor phase, or the initial material may ilrstbe cracked in the liquid phase and subsequently in therapor phase. 'The material may also be subjected to a pure dehydrog'enation treatment or both to a cracking and a dehydrogenation treatment. I p

'- In all these cases suitable cracking or dehydrogenation catalysts may be applied, if desired. In these various ways liquid crack d products may be obtainedithe oleflne content of which may'amount upito nearly 100%, for example or the remainder being substantially saturated hydrocarbons. if desired, the initial materlal or the unsaturated products obtained therefrom by the heat treatment may be sub-v 5 jected to a suitable pretreatment. Thus the wax content of the initial material may be enriched by a treatment with selective solvents for the aromatics, or the unsaturated prod- 'ucts obtained in the heat treatment of the initial 5 material may be treated with small amounts of with the production ofsuch H2804 or AlCla, to remove certain highly unsaturated compounds, such as di-olefines with conjugated double bonds.

The unsaturated products obtained in the heat treatment of the waxy initial material may be 5 reacted with the strong polybasicacids as a whole, but it is preierred. to fractionate these unsaturated products into various fractions and to reactiiquid fractions, such as the C0-C9, the C9-Cl2 and the Cue-Cm fractions, separately 9 with the strong polybasic acids.

Suitable acids which may be used as reaction media for oleflnes in the preparation of the acid alkyl esters to which our invention is applicable,

arepolybasic mineral-acting acids of which sul- 15 iuric, pyrosulfuric, phosphoric, pyrophosphoric,

- and the likeare typical. The concentrations in which such acids are customarily used for the absorption of olefines'vary widely depending upon the character of the olefine or oleflnes involved, 20 the oleflnic concentration, and the temperature at which the absorption is carried out." In the practice of our invention we preferably adjust the conditions of olefine absorption, in the conventional manner, so that substantially only ab- 25 sorption of the olefines is effected, and tar formation and other undesirable side reactions are reduced to a minimum. The resulting acid liquor usually comprises an aqueous solution of neutral and/or acid esters with some free mineral-acting 3o acid and may or may not contain small amounts of polymer, free alcohol and/or verylow percentages of free hydrqcarbons.- Operating as well as economic advantages result from the removal of free acid from the oleflne absorption product prior to formation of the 'desired'salt. This may be eflected in several ways. Advantage may be taken of the process described in copending application, Serial No. 27,048 filed June 17, 1935 by Tulleners, whereby the'acid is selectively removed in a free state by extraction with a small quantity of water, for example; Besides the absence of sulfate in the final product, this procedure also provides the possibility of economic regeneration of the excess acid. Furthermore, the coloring constituents present in the absorption product are removed in the aqueous layer simultaneously with the free acidwith the result that 'a finished product of much improved appearance is obtaine Alternatively, the free acid present in the olefine absorption product may be removed by sel lective neutralization, as by treatment with an alkaline agent such as Glauber's salt, preferably after the addition at water or ice. The sodium 55 blsuliateformed separates as an layer which may be drawn oil from the layer'containing the alkyl esters. This procedure prevents the final product being adulterated with sulfate 5 to any appreciable extent.

The separation of the phases in this method of procedure may be facilitated by the addition a small quantity of a substance which alters the interfacial tension, such as ethyl ether, amyl 10 alcohol, and the like.

To insure the absence of neutral alkyl esters in the finished product several alternative procedures may be employed, For example, the solution containing neutral alkyl esters and salts of 16 acid alkyl esters may be extracted withsuitable I selective solvents for the former such as benzene, gasoline fractions, saturated as pentane, hexane, etc., their admixtures, and the like. This extraction may be carried out in 20 either the presence or absence 0! free acid. An-

other'eifective method oi.procedure comprise dilution of the, preferably acid-tree, oleflne absorption product with a relatively large amount of water whereby two phases will be formed. The

25 phase containing the neutral esters and any poll!- mers present may be drawn on and the-aqueous phase containing substantially only acid alwl esters may then be used to prepare the desired salt by any of the descrlbedmethods. This sens-- 30 ration of-phases can conveniently be eilected by dilution with a solution or a basic compound of agent at anelevated temperature. Thisprocedure fliers special advantages wherever it may bemoredesinbletomakeuseoitheacidalhl esters tor the preparation of other products, such as alcohols, and the like. When it is not ac desired to prepare a diii'erent product or products mm the acid alkyl esters the conversion of the neutral esters into alkyl salts may advanw seously be eilected without separation or the two types of esters. Thus the olefl'ne absorption product, preferably after bdng freed oi itsexcess acid.-ii present, may be treatediwith a solution olabasiccompcimdofthemetaliromwhichthe' alkyleatersaltistobeprepared. Thebaseis added in suflicient amount to do decommtion ottheneutralalkyl esterspreaent andthe mixture is heated until/aid! is substantially complete..'1hereooveryandpurio ilcationoi the alhlestersaltsiormedlromboth.

car material. The saidupp layer isintrodescribed. Bythb isaniniurioust ineutnleste'rs) oith'el flnalllroductelimlnmbutalsqthe yield oi'the.

desired alkyl acid is increased.

The iollowing examples 70 same procedm'e'smaybemsdto-m mixture is then introduced .into a separator, in

, od or operation,

perature range of about 160 to 220 C. The benzine fraction was obtained by vapor phase cracking of paraflln cakes and had a bromine value. according to McIlhiney, of 94. The acid addition was carried out slowly while thoroughly cooling and stirring the mixture for about one and a half hours so that a temperature of about 5 to C. was maintained therein.

The absorption-product obtained was poured on to 3.3 kgs. of ice which caused the temperature 10 to rise to about 25 C. Alter standing about fitteen minutes a division into two layers took place in the mixture. These layers were. separated. The lower layer was found to be about a 62% sulfuric acid solution containing much of the coloring matter which had been present in the absorption product.

The upper layer was neutralized with a 40% sodium hydroxide solution of which about 3.14 liters were required. Any excessive rise in tem- 2; perature during neutralization was avoided by. cooling. The dialhl sulfate content of the neutral product was determined by analysis and it was found that 1.6 liters of the 40% sodium hydroxlde solution would be required to effect its saponiflcation.- Thisamount of alkali was then I .added and the solution was heated to a tempera ture of about 95 C. and maintained atthat temperature for about three hours. The product of the reaction was diluted with about 20 liters of water and again heated at 95 C. for some time. Two phases were formed in this operation. After heating these phases .were allowed to stratiiy and the upper phase (3.12 kgs.) comprising products of polymerization, alcohols, etc. was separated from the lower layer which was a clear solution of sodium alkyl sulfates. This solution could be further diluted with water without be-' coming cloudy and onevaporation under vacuum-yielded l9 kgs. of air-dried product.

- Examples 11 v A crack distillate traction bofling between 220 and 300 C. obtained by cracking crude parailin cakes in the vapor phase at 560 'C., substantially containing alkenes with 13 to 18 C-atoms, with a bromine number Mcnhiney=50.5, corresponding to a percentage of alkenes of .approximately 68, and a molecular quantity of 90% sulfuric acid, are intensively mixed in -a reaction vessel. The reaction vessel is kept at a temperature of 25' C. by cooling, the time-ofreaction being about 1 hour. After this about- 10% by weight oi. water is added to the mixture. whilst the temperature is kept at 25 C.- The which two layers are iormed,'the lower consistj in: of an approximate 56% H1804 solution and the upper layer of acid and neutral, alkyl sulr fates, polymerization products and unconverted 60 I duc ed, simultaneouslywith an excess of lye, while intensively-stirring, into a reaction vessel, which is'k ept at about 100 C.- The time of reaction lsabout 6 hours. In the reaction vessel the, neutralization of the'alkyl acid ester as well as the saponincation of the neutral alkyl ester takes is taken that an alkaline reaction prevails the reaction vessel, the final e .70 :acte't'as The alkyl acid ester salt in pro ucty'etshqyinilalslightan an. mediinnbeingresistantagainstheatobtained is mixed inatherel no risk or a decomposition or this g sait. The reaction mixture with an equa quantity of water and introduced into a separator, where the mixture is separated into an upper layer insoluble in water and an aqueous solution of sodium alkyl sulfate. The separator is thereby likewise keptat 100 C. The sodium alkyl sulfate may be obtained as a dry powder, e. g. by using a spraying and drying apparatus. The yield of sodium alkylsulfate, calculated on the quantity of olefines present in the initial material, amounts to about 59% of the theoretical yield. The process is carried out continuously.

The salts of the alkyl esters of polybasic mineral-acting acids which may be prepared by our invention may be used, individually or as mixtures, with or without other agents, for a great many widely different purposes; They have exceptional wetting and emulsifying power. They salts of fatty acids, they furnish esters and may alsobe used for the preparation of pure a1cohols. For the latter purpose they may be dissolved, for example, in water, and yield alcohols after acidification and heating.

While we have in the foregoing described in some detail the'preierred embodiments of our invention and some variants thereof, it will be understood that this is only for the purpose of making the invention more clear and that the invention is not to be regarded. as limited tothe details of operation described, nor is it de pendent upon the soundness or accuracy of the theories which we have advanced as to the ad'- vantageous results attained. n the other hand, the invention is to be regarded as limited only by the terms of the accompanying claims, in which it isour intention to claim allnovelty inherent therein as broadly as is possible in view of the prior art.

We claim as our invention: 1. Process for preparing wetting agents and detergents comprising cracking a paraflini'c petroleum fraction selected from the group con- They may sisting of petrolatum and parafdn wax first in .the liquid phase and subsequently in-the vapor phase to provide a cracked fractioncontaining a mixture of olefines having more than six carbon atoms per molecule, reacting said mixture,

of olefines with a-strong inorganic polybasic acid and neutralizing the resulting mixture of alkyl acid derivatives of said acid.

2. Process for preparing wetting agents and detergents comprising cracking a paraflinlc petroleum fraction selected from the group consisting of petrolatum and paraffin wax first in the liquid phase and subsequently in the vapor phase to provide a cracked fraction containing a mixture of olefines having more than six carbon atoms per molecule, reacting said mixture of olefines with sulfuric acid to remove the more reactive unsaturated components, treating the remaining substantially normal olefines. with a strong inorganic polybasic acid and neutralizing the resulting mixture of alkyl acid derivatives of said acid.

3. Process for preparing wetting agents and detergents comprising cracking a'paraflinic petroleum fraction selected from the group consisting ofpetrolatum and paraflin wax to provide a cracked fraction containing a mixture of :olefines having more than six carbon atoms. per

molecule, reacting said mixture of-olefine's with sulfuric acid to selectively remove unsaturated components more reactive than the normal olefines present, reacting the remaining substantially normal olefines with a strong inorganic.

polybasic acid and neutralizing the resulting mixture of alkyl acid derivatives of said acid.

4. Process for preparing wetting agents and detergents comprising cracking a paraffinic petroleum fraction selected from the group consisting ofpetrolatum and parafiin wax to provide a. cracked fraction containing a mixture of olefines having more than six carbon atoms per molecule, substantially selectively removing at least a part of the unsaturated compounds more reactive than the normal olefines contained in said fraction, reacting the remaining substantially normal olefines with sulfuric acid and neutralizing the resulting mixture of alkyl' acid sulfate derivatives.

Anamuns JOHANNES m PESKI. ANTON JOHAN 'runnannas. 

